664140065 has 16 divisors (see below), whose sum is σ = 832761216. Its totient is φ = 507513600.

The previous prime is 664139981. The next prime is 664140073. The reversal of 664140065 is 560041466.

It is not a de Polignac number, because 664140065 - 2²⁰ = 663091489 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89705 + ... + 96825.

It is an arithmetic number, because the mean of its divisors is an integer number (52047576).

Almost surely, 2^664140065 is an apocalyptic number.

It is an amenable number.

664140065 is a deficient number, since it is larger than the sum of its proper divisors (168621151).

664140065 is a wasteful number, since it uses less digits than its factorization.

664140065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7960.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 664140065 is about 25770.9150982265. The cubic root of 664140065 is about 872.4754726920.

The spelling of 664140065 in words is "six hundred sixty-four million, one hundred forty thousand, sixty-five".